Dispersions of polyurethane-vinyl polymer hybrids made by radically initiated copolymerisation of ethylenically unsaturated monomers and polyurethane macromonomers have been known, i. a. from EP 0 522 420 A2. These dispersions have been used in a variety of applications, including preparation of basecoats in multilayer coatings used for the painting of cars. In such multilayer applications, a key property of the coating layers is their intercoat adhesion, in this case, between the primer-surfacer layer, and the basecoat, and the basecoat layer and the clearcoat which is the topmost coating layer. Another property that is important for the basecoat is its water and humidity resistance, which needs constant improvement.